216381964 has 12 divisors (see below), whose sum is σ = 378816984. Its totient is φ = 108148544.

The previous prime is 216381961. The next prime is 216382039. The reversal of 216381964 is 469183612.

216381964 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (216381961) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2724 + ... + 20980.

It is an arithmetic number, because the mean of its divisors is an integer number (31568082).

Almost surely, 2^216381964 is an apocalyptic number.

It is an amenable number.

216381964 is a deficient number, since it is larger than the sum of its proper divisors (162435020).

216381964 is a wasteful number, since it uses less digits than its factorization.

216381964 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21224 (or 21222 counting only the distinct ones).

The product of its digits is 62208, while the sum is 40.

The square root of 216381964 is about 14709.9273961499. The cubic root of 216381964 is about 600.3534621037.

The spelling of 216381964 in words is "two hundred sixteen million, three hundred eighty-one thousand, nine hundred sixty-four".